This week, President Obama replaced his top commander in Afghanistan. General Stanley McChrystal resigned after a year in command of United States and NATO forces. To replace him, the president chose the general to whom General McChrystal reported. The Senate is expected to quickly confirm General David Petraeus to lead the nearly nine-year-old war.

The last president to remove a war commander was Harry Truman. In nineteen fifty-one he dismissed General Douglas MacArthur during the Korean War. But that was a dispute over policy.

General McChrystal lost his job over comments made to and in the presence of a reporter from Rolling Stone magazine. The general and his aides spoke disrespectfully about several administration officials. The general was quickly ordered to the White House to meet Wednesday with President Obama.

BARACK OBAMA: "I welcome debate among my team, but I will not tolerate division."

The president said he had considerable regret in accepting the resignation of "one of our nation’s finest soldiers." But he said his responsibilities as commander-in-chief led him to his decision.

BARACK OBAMA: "The conduct represented in the recently published article does not meet the standard that should be set by a commanding general. It undermines the civilian control of the military that is at the core of our democratic system."

President Obama announcing the replacement of General McChrystal with General David Petraeus

The president says the change is not a change in policy. He says General Petraeus understands that strategy because he helped shape it.

General Petraeus is known for his political as well as military skills. Experts credit him with a successful counterinsurgency strategy in Iraq in two thousand seven and two thousand eight. Counterinsurgency involves military action but also depends on civilian relationships to succeed.

The Afghanistan policy calls for establishing security in cities and towns, protecting civilians even if it means more danger for coalition troops. It also involves training local security forces and strengthening the government.

Last month, General Petraeus talked about the situation.

DAVID PETRAEUS: "As was the case in Iraq, the reality is that everything in Afghanistan is hard. It's hard all the time, and it typically gets harder before it gets easier."

General McChrystal was one of the relatively few American officials to develop a good relationship with Afghan President Hamid Karzai. But he never did the same with the American ambassador, Karl Eikenberry, a former commander in Afghanistan.

On Wednesday, President Obama repeated the policy agreed to last fall.

BARACK OBAMA: "We are going to break the Taliban's momentum. We are going to build Afghan capacity. We are going to relentlessly apply pressure on al-Qaida and its leadership, strengthening the ability of both Afghanistan and Pakistan to do the same."

Admiral Mike Mullen, the Joint Chiefs chairman, says the United States should know by the end of this year whether the strategy is working.

If all goes as planned, withdrawals could begin by next July. But insurgent attacks have increased and progress has been slower than expected in the south.

Thirty thousand more American troops are joining the war. But public support is down and concerns in Congress are up.

June is the deadliest month yet for international forces in Afghanistan. And problems continue with the development of the Afghan security forces and with corruption among Afghan officials.